Chemical impact-sensitive fuze



Jan. 14, 1969 A. F. MARDARELLO ETAL CHEMICAL IMPACT-SENSITIVE FUZE Filed Aug. l, 1966 INVENT'OR ALFRED F. MARDARELLO BY ALLEN 35x21 "4i/@My fm. LM/.mgm/ww ATTORNEYS:

United States Patent 7 Claims ABSTRACT OF THE DISCLOSURE An impact sensitive fuze which employs an explosive comprising lead azide, RDX, a thickener, and glass powder, land a desensitizer mixed therein of trichloroethane or difluorodichloromethaue which is controllably volatilized at a predetermined time to render the fuze sensitive.

This invention relates to a munitions fuze and particularly to an impact sensitive fuze.

An object of the present invention is to provide a simplified impact sensitive fuze which is free of any moving parts.

Another object of the present invention is to provide a fuze of the above type which is safe to handle prior to use.

A further object of the present invention is to provide a fuze of the above type which will fbecome active at a predetermined time after being subjected to the atmosphere.

Still another object of the present invention is to provide a fuze of the above type which uses as its initiating charge an impact sensitive explosive containing a desensitizer intim-ately commingled therewith in an amount which will evaporate when the fuze is exposed to the atmosphere for a predetermined period of time, thereby rendering the initiating charge sensitive to shock and impact.

Yet another object of the invention is to provide a fuze constituting a completely self-contained munition.

Further .objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should Ibe had to the following detailed description taken in connection with the accompanying single drawing which is a view in elevation and in cross section of lan explosive device using a fuze embodying the present invention.

Referring to the single drawing, 10 is a hollow body having a closed lower end and an open upper end. The body 10 contains an explosive charge 12 which is an explosive sought to be detonated. The Icombination of the Ibody 10 and charge 12 is not part of the present invention ibut is described merely to place the inventive fuze 14 in an illustrative setting. The fuze 14 comprises a hollow cap or housing 16 closed at its lower end and open at its upper end. The housing 16 is adapted to fit securely over the upper end portion of the body 10. The lower end portion of the housing 16 extends into the body 10 and communicates with the explosive charge 12. The housing 16 contains an impact sensitive explosive mix 18. The mix 18 can be of a nature and in a sufficient amount that when the mix 18 is initiated the explosive wave will penetrate through the housing 16 and 3,421,441 Patented Jan. 14, 1969 ICC detonate the explosive charge 12. A disc 20 is adapted to lit securely in the upper end portion of the housing 16 and functions to retain the explosive mix 18 securely Within the housing 16. The disc 20 contains a perforation or a plurality of perforations 22 therethrough, the function of which will become apparent .further on in the course of this description.

The explosive mix 18 contains a desensitizer of a nature compatible with the type of impact sensitive explosive used. The desensitizer must 1be of a volatile nature, such as diuorodichloromethane or trichloroethane. The reason therefor is that when the fuze 14 is subjected to the atmosphere the desensitizer will evaporate rendering the explosive mix 18 sensitive to shock yor impact. The choice of desensitizer Will determine the time required to arm the fuze, that is the more volatile the desensitizer the quicker the explosive mix 18 will become impact sensitive.

One explosive mix 18 found to perform satisfactorily consisted essentially of the following ingredients in ap- The above explosive mix 18 is an impact sensitive mix and to render it desensitized prior to oper-ation 1,1,l-trichloroethane was intimately -commingled therewith in such quantity as to completely desensitize the mix 18. However, where it is desired to obtain a rapid desensitization of the explosive mix 18 dfluor-odichloromethane or other volatile solvents can ybe used, such as the commercialy available fluorinated hydrocarbons sold under the trademark Freon.

The device described above and illustrated in the single drawing could be readily incorporated as a submunition in a parent carrier. This su'bmunition would remain within the parent carrier sealed from the atmosphere. Means lcould be provided in the parent carrier for ejecting the su'bmunition at a predetermined point along the trajectory of the parent carrier. Thus, the fuze 14 would remain inactive, that is, the explosive mix would lbe desensitized, during storage, launch, and flight of the parent carrier. Upon ejection from the parent carrier the fuze 14 Ibecomes eX- posed to the atmosphere and the desensitizer due to its volatile nature, begins to evaporate. The gases resulting from evaporation of the desensitizer egress from the housing 16 through the perforations 22 in the disc 20. When the desensitizer evaporates, the explosive mix 18 is fully sensi tive to shock and impact. Initiation of the explosive mix 18 is accomplished when the fuze 14 strikes the earths surface. The explosive mix 18 then initiates the charge 12.

It may be noted that there are no theoretical limits to the size or configuration of the fuse 14, It can be made as small or as large as desired and in whatever shape needed, i.e., spherical, rectangular, etc. It can Ibe used in a variety of tactical roles ranging from the main fuze of an artillery or rocket projectile to a fuze that can be used in small calibre bullets. The fuze 14 can be used to initiate high explosives, ignite propellant, operate mechanisms (such as to rebound mechanisms, for example) or |by itself with a suitable fragmenting wall so that it is a completely self-contained projectile. Other applications of the inventive fuze 14 can be readily realized by those skilled in this art, such as on chemical, bac teriological, or radiological munitions, for example.

We claim:

1. An impact sensitive fuze comp-rising a housing defining an opening at its upper end;

an impact sensitive explosive mix in said housing,

said mix containing a volatile desensitizer intimately commingled therewith and in an amount to substantially completely evaporate when said fuZe is subjected to the atmosphere for a predetermined period of time, whereby upon evaporation of said desensitizer, said mix is rendered sensitive to shock and impact, and wherein said mix consists essentially of about 18 percent by weight of lead azide, about 29 percent by Weight of RDX, about 3 percent by weight of thickener, and about 50 percent 'by weight of powdered glass.

2. A fuze according to claim 1 including means in said opening for retaining said mix within said housing while allowing egress of gases produced by the evaporation of said desensitzer.

3. A fuze according to'c'laim Z wherein sa'id'desen'sitizer is a material selected from the group consisting of trichloroethane and diuorodichloromethane.

4. A fuze according to claim 3 wherein said trichl'oroethane is 1,1,1-trichloroethane.

5. A fuze as set forth in claim 2 wherein said retaining means comprises a perforated disc.

6. An impact sensitive fuze comprising a housing defining an opening at its upper end,

an impact sensitive explosive mix in said housing, said mix comprising lead azide, RDX, a thickener,

References Cited UNITED STATES PATENTS 2,146,033 2/'1939 VSeavrey'et al; -;L'.; V149-'35 X 2,368,310 1/1945 Lecky et al. 102-73 X 2,424,970 8/ 1947 Church et al 102-73 X 2,958,277 11/1960 Snelling 102-90 X BENJAMIN A. BORCHELT, Primary Examiner.

GERALD H. GLANZMAN, Assistant Examiner.

U.S. Cl. X.R. 

